refactor StreamDetails type and fix functions accordingly

Author: Jamil Maqdis Anton

src/Append.fs

@@ -1,6 +1,6 @@
 namespace SqlStreamStore.FSharp
 
-open System
+
 open SqlStreamStore
 open SqlStreamStore.Streams
 
@@ -11,26 +11,34 @@ type MessageDetails =
       jsonMetadata: string }
 
 and Id =
-    | Custom of Guid
+    | Custom of System.Guid
     | Auto
 
 module append =
     let appendNewMessage: IStreamStore -> StreamDetails -> MessageDetails -> Async<AppendResult> =
         fun store streamDetails messageDetails ->
-            let id: Id -> Guid =
+            let id: Id -> System.Guid =
                 function
                 | Custom guid -> guid
-                | Auto -> Guid.NewGuid()
+                | Auto -> System.Guid.NewGuid()
 
             let createMessage: MessageDetails -> NewStreamMessage =
                 fun msg ->
                     match msg.jsonMetadata with
                     | "" -> NewStreamMessage(id msg.id, msg.type_, msg.jsonData)
                     | metadata -> NewStreamMessage(id msg.id, msg.type_, msg.jsonData, metadata)
 
+            let toVersion: Version -> int =
+                function
+                | Version.None
+                | Version.Any -> ExpectedVersion.Any
+                | Version.EmptyStream -> ExpectedVersion.EmptyStream
+                | Version.NoStream -> ExpectedVersion.NoStream
+                | Version.SpecificVersion version -> version
+
             let append: IStreamStore -> StreamDetails -> MessageDetails -> Async<AppendResult> =
                 fun store stream msg ->
-                    store.AppendToStream(stream.streamName, stream.position, createMessage msg)
+                    store.AppendToStream(stream.streamName, toVersion stream.version, createMessage msg)
                     |> Async.AwaitTask
 
             append store streamDetails messageDetails

src/Read.fs

@@ -10,20 +10,31 @@ type ReadingDirection =
     | Backward
 
 module Read =
+    let toStartPosition: int option -> int =
+        function
+        | Some position -> position
+        | None -> 0
+
     let readFromStreamAsync: IStreamStore -> ReadingDirection -> StreamDetails -> int -> Async<ReadStreamPage> =
         fun store readingDirection streamDetails msgCount ->
             match readingDirection with
-            | Forward -> store.ReadStreamForwards(streamDetails.streamName, streamDetails.position, msgCount)
-            | Backward -> store.ReadStreamBackwards(streamDetails.streamName, streamDetails.position, msgCount)
+            | Forward ->
+                store.ReadStreamForwards
+                    (streamDetails.streamName, toStartPosition streamDetails.startPosition, msgCount)
+            | Backward ->
+                store.ReadStreamBackwards
+                    (streamDetails.streamName, toStartPosition streamDetails.startPosition, msgCount)
             |> Async.AwaitTask
 
     let readFromStreamAsync': IStreamStore -> ReadingDirection -> StreamDetails -> int -> CancellationToken -> Async<ReadStreamPage> =
         fun store readingDirection streamDetails msgCount cancellationToken ->
             match readingDirection with
             | Forward ->
-                store.ReadStreamForwards(streamDetails.streamName, streamDetails.position, msgCount, cancellationToken)
+                store.ReadStreamForwards
+                    (streamDetails.streamName, toStartPosition streamDetails.startPosition, msgCount, cancellationToken)
             | Backward ->
-                store.ReadStreamBackwards(streamDetails.streamName, streamDetails.position, msgCount, cancellationToken)
+                store.ReadStreamBackwards
+                    (streamDetails.streamName, toStartPosition streamDetails.startPosition, msgCount, cancellationToken)
             |> Async.AwaitTask
 
 module ReadExtras =

src/Types.fs

@@ -1,3 +1,15 @@
 namespace SqlStreamStore.FSharp
 
-type StreamDetails = { streamName: string; position: int }
+
+[<RequireQualifiedAccessAttribute>]
+type Version =
+    | None
+    | Any
+    | EmptyStream
+    | NoStream
+    | SpecificVersion of int
+
+type StreamDetails =
+    { streamName: string
+      startPosition: int option
+      version: Version }